NDI Watcher

The NDI Watcher actor uses NewTek’s NDI video streaming technology to allow you to receive NDI video streams broadcast from other computers or devices.

This actor is in public beta. There may be bugs that affect performance and/or lead to crashes. Because of this, we do not recommend using this actor for public performances or installations. If you do choose to use this beta version for such performances, you do so at your own risk.

Apple silicon (ARM/M1)

The macOS version of this plugin has been compiled to run natively on both Intel-based and Apple silicon based computers.


Follow the instructions in the file Installation Instructions.rtf

NDI 5 vs. NDI 4 vs. NDI 3

Isadora 3.1 and later will use NDI v5, while Isadora 3.0.7  uses NDI v4 and Isadora 3.0.6 and before use NDI v3. Because of this, multiple versions of the plugin are given in this distribution.

Take care to install the correct version of the plugin for your version of Isadora, otherwise the plugin will not function or may not appear in Isadora at all.

The name of the plugin shown in Isadora makes it clear which version of the plugin you are using. It will be called NDI 5 Watcher for NDI 5 version, and NDI 4 Watcher for the NDI 4 version.

You cannot have multiple versions of the NDI Watcher plugin installed at the same time!

Usage Instructions:

  1. Add the actor to the scene, and click in the value box to the left of ‘ndi source’.
  2. A popup menu with the currently available NDI servers will appear.
  3. Select the NDI server you wish to receive
  4. Connect the ‘video’ output to the desired destination actor.

Known Limitations

Because the NDI 3 Watcher (required for Isadora 3.0.6 and earlier) uses NDI 3, it cannot receive from the NDI Camera app for iOS.

NDI Best Practices

NDI is a great technology, but it can’t work miracles: sending video requires both bandwidth and a very fast connection. You simply can’t expect to send full resolution HD video on a shared WiFi connection clogged by others! Follow these best practices to get the best results with the NDI on a network.

Whenever Possible, Use a Hardwired Gigabit Ethernet Network

To transmit full bandwidth, low latency video using NDI generally requires a hardwired gigabit Ethernet network. Using anything less than this can give less than poor results.

If You Must Use WiFi, Get a Dedicated Router

If you must use WiFi, then please work with a WiFi router dedicated to allowing NDI devices to communicate. Attempting to use NDI on a university or other public network that is filled with other people’s data is a recipe for disaster. If you plan to use WiFi for NDI, get an inexpensive WiFi router and leave it disconnected from the Internet; even when not online, the router will allow your computer and other NDI sources or destinations to communicate.

For Isadora
Actor version(s)
December 06 2019
last updated
March 29 2023
345.24 KB
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    ziopixel onApril 03, 2021 at9:40 said:


    it seems that the NDI 4 version lock the NDI input actor to 640×320 px whatever input resolution is provided, is there anyway to unlock it? or am I doing something wrong?

    Thank you